Inductance system



March 3, 1931. L. A. GEBHARD 1,794,606

INDUCTANCE SXSTEM Fil ed Nov. 12. 1929 a Sheets-Sheet 1 45 INVENTOR.

7 7 filo Idea. $266M,

ATTORNEY March 3, l93 1. GEBHARD 1,794,606

INDUCTANCE SYSTEM Filed Nov. 12. 1929 5 Sheets-Sheet 2 UTE-#5;

INVENTOR.

I ROM/i0 a. 9466M,

BY-M m ATTORNEY M6161; 3, 1931. GEB'HARD I 1,794,606

INDUCTANCE SYSTEM V 'INVENTOR. 9044 10 61, BY

A TTORNEY Patented Mar. 3, 1931 UNITED STATES My invention relates broadly to high pow-' or radio transmission apparatus and more particularly to an inductance change system for high frequency signaling circuits.

' One of the objects of my invention is to provide a construction of inductance change system for high power, short wave radio transmitters in which losses may be maintained at a minimum by the circulation of 1 cooling fluid through the active inductance in the transmitting circuit.

Another object of my invention is to provide an inductance change system for radio transmitters in which inductances of different effective values may be electrically connected in the transmission circuit and a cooling fluid supplied to the individual induc-.

tances for maintaining the operation of the transmitting circuits under conditions of minimum loss.

A further object of my invention is to provide a construction of inductance change system in which a multiplicity of inductances, each having different values, ma be individually and selectively connected in the transmitter for operation of the transmitter at predetermined frequency. and a cooling fluid supplied through'the inductance whic is in use for the operation of the transmitter circuit at maximum efficiency.

Other and further obj ects' of my invention reside in the construction of inductance change system for high frequency, high power transmitters and the means for circulating a cooling fluid through a selected inductance in the transmitter system as set forth more fully in the specification hereinafter following by reference to the accom panying drawings, wherein:

Figure 1 is a plan-view of the inductance change system showing one of the inductances coupled for the supply of cooling-fluid theretoyFig. 2 is a cross-sectional view on line =22 of Fig. 1 showingthe arrangement of the inductance units which are available for connection in the transmitter circuit and the arrangement of a selected inductance connected in the transmitter circuit in position for receiving cooling fluid which passes through the inductance; Fig. 3 shows the 111- PATENT OFFICE LOUIS A. GEBHABD, 01' WASHINGTON, DISTRICT OF COLUKBL A, ASSIGI IOB TO WIRED v RADIO, INC., 01' NEW YORK, N. Y., A CORPORATION 01' DELAWARE nmuc'rmcn srsrim Application. filed Iovember 1:, 1020. Serial in. 406,708.

ductance system rocked to a position where the cooling fluid connection can be disconnected preparatory to the shift of frequency of the transmitter; Fig. 4 is a cross-sectional view on line 4-4 of Fig. 1, illustrating the control means for the valves by which the passage of fluid fromthe fluid cooled high power tube system to the individual inductance units may be controlled; Fig. 5 is a fragmentary cross-sectional view illustrating the control valves,illustrated in Fig. 4, moved to an-extreme opposite position in which the inductance is unlocked with respect to the feeder pipes leading from the high power fluid cooled tube system; Fig. 6 is a cross-secof the terminus of the inductance looking in the, direction of line 10-10 of Fig. 7; and Fig. 11 is a side elevation of the terminus of the inductance.

In hi h power radio transmitters covering a wide equenc band the output inductance must be change for operating the transmitter on different frequencies in the band. In high power operations it is also necessary to use fluid 'coo ed tubes, the cooling fluid of which is supplied normally through an insulating tubing wound on a frame and connected at one side to the liquid supply and at the other side to the liquid jacket in which the tubes are placed. This arrangement, however, involves a certain amount of loss due to the action of the radio frequency energy near the point where the insulating tubing is connected to the liquid jacket. This loss may be in the insulatin material of which the tube is made or in t e cooling liquid itself or both.

In the development of high frequency transmitters, I have found that a considerable increase in efiiciency may be obtained by cooling the output inductances in the transmission circuit and eliminating the cooling and extremely short connections may be made by the direct connection of the inductance unit with the fluid feeder pipes which connect to the cooling jackets of the high power tube. I provide. means for closing the fluid ferent value.

feeder pipes from the high power tube system when it becomes necessary to change the eflective inductance in the-transmitter cir-. cuits. Each inductance has the end thereofequipped with a valve and as the inductances are changed the valves are closed to prevent leakage of fluid during the interchange of one inductance coil for an inductance coil of dif- The equipment which I- employfor locking aninductance in the fluid cooling circuit may be actuated rapidly for the removal of one inductance from the transmitter circuit and the substitution of an inductance of different frequency in the transmitting circuit. A complete changein frequency may be effected with minimum delay andthe' operation of the transmitter circuit at maximum eificiency is insured by virtue of short interconnecting leads and the control .of the temperature. of both the inductance and the high power tubes which are operated in the transmitter system.

Referring to the drawings in deta-il, ref- I erence characters 1 and 2 designate the fluid cooled tube systems which may be associated with the condenser system 3. An insulating frame 4-is provided adjacent the fluid cooled tube systems 1 and 2, the frame being angularly movable about an axis within limits defined by pins 6 and 7. Insulating frame 4 consists of a pair of arms between which there is'journ'aled a shaft 8 which projects through a front panel 9' of the-transmitter with a control knob 10 thereon by which shaft 8 maybe rotated. The shaft 8 carries an insulating frame structure constituted by end members 11 and 12 between which in-- sulati'ng supports or arms 13, 14, 15 and 16 we tend. Inductances of differing values are supported on the respective arms, that is the largest inductance coil 17 is shown mounted on insulating arm 13; a smaller inductance 18 is mounted on arm 14; a smaller, inductance 19 is located on arm 15 and a still smaller inductance 20 is carried by arm .16. The inductances are formed in twin conduc tor metallic tubing secured together by any suitable method such as brazing orsoldering.

These two tubes'provided an inlet and an outlet circuit for thecooling fluid supply as well as a path for the electrical circuits through the inductance and through the transmitter. Near the center ofeach coil the two tubes forming the twin'conductor of the coil are spread to-enable fluid connections to be made and 29 and 30 atv the opposite end. At the center of the coil, inlet and outlet connections are provided as represented at 31 and 32. In a similar manner inductance 19 has inlet and outlet pipe connections 33 and 34 at one end, and 35 and 36-a't' the opposite end, with pipe connections 37 and 38 adjacent the center of the inductance. The fluid connections to the cooling jackets of electron tubes 1 and 2 and to the centers of the coils, terminate at 81-82, 39.40 and 4142. Each of the terminal pipes is provided with a coupling head 43 which has been illustrated more clearly in Figs. 6-8. Each of the coupling heads 43 are angularly movable by means of lever arms 44 which are shiftable by means of'a plunger rod 45, of insulating material,

horizontally movable from the front of the panel mounting through slot 46 by means of knob 47 The couplinghead 43 is maintained in position on the end of each of the pipes 3742, inclusive, by means of bushing 48 which may be fixed adjacent the terminus of each pipe.

The construction of the terminus of the pipes 81, 82,40, 41 and 42 may be understood more clearly by reference to Figs. 67-9. The terminus of each pipe 81 is provided with a flange 50 which provides an abutment for the end of the coupling head 43. The coupling member 51 is internally screw threaded as represented at 52 to engage the external screw threads 5.3 on the coupling head 43 in such manner that the coupling member 51-is free to be shifted angularly with themovement of coupling head 43. vThe coupling member.

51 is provided with inwardly directed projections 54 which are alternately positioned around the inner periphery-of the coupling member 51 and are spaced to provide gaps 55 which conform with the projections 56 in-' tegrally formed on the end of the tubular inductance as represented at 28. The ends of the tubular inductances and the fluid inlet and discharge pipeslare each provided wi h a valve mechanism normally maintaining the fluid passages closed preparatory for automatic opening when the ends of the inductance are brought into registering relation with the fluid inlet and discharge terminal pipes. I have shown the arrangement of valve mechanism in the aligned passages in Figs. 6 and i'. The terminus of pipe 81 is provided with a spider 57 positioned interiorly of the pipe 81 adjacent the end thereof, the spider being apertured at 58 for the passage of fluid and iaving a pin 59 supported therein and arranged to maintain a spring 60 in central position. which sprin acts against ball-valve 61 tendin" to move t 1e ball valve toward the seat 62 of sleevc member 63 which screw threaded to engage the internal screw threads on the end of the terminus 81. The sleeve 63 is provided with a spider 64 which supports the slidable member 65. The slidable member 65 has ahead 66 which may be engaged by the head 67 which is mounted in the. end of the fluid passage 28 of the inductaneeunit. The head 67 is carried by a stem 68 slidable in spider 69 which is supported on sleeve 70 which carries valwe seat 71. The ball valve 7 2 is normally wedged against valve seat 71 or spring member 73 which is supported on central pin 74 mounted on spider 75. The spider 75 is suitably aperture-d for I ductance thereby closed. lVhen the coupling member 51 is rotated by moving horizontal bar which communicates motion through coupling head43, a. position may be reached at which the projections 56 on pipe 28 may pass between the inwardly directed projections 54 on coupling member51 enabhng the heads 67 and 66 to abut. one with respect to another. Continued movement of the shiftable frame 4 toward the stationary terminus pipes introduce pressure between the heads 66 and 67 forcing the ball valves 61 and 72."

from their seats a ainst the pressure of springs and 7 3 and completing the passage for the flow. of cooling flllld from the terminus pipe 37 through the tube 28 of the in-:

ductance unit. The head 66 is a'pertnred at 66a and head 67 has aligned apertures at 67a thus forming no obstructions to the passage of fluid. The pins and 66 are limited intheir movement by do 656 and 68?). A ket 77 fits into an aligned annular recess 8 in sleeve thereby insuring a water tight joint between the inductance and the .fluid su ly terminus. e ope ing mechanism is shown more clearly in Figs. 4 and 5 where Figure 4 indicates the inductance unit locked in position with respect to the stationary fluid supply and discharge pipes, and Figure 5 illustrates the control bar 45 moved to a position where the inductance unit is about to be connected to the fluid supply or discharge pipes, or in position where the inductance units are about to be disconnected and removed from the stationa fluid discharge and supply pipes. The locking bar 45 is notched at 45c and 45b to enable the bar to be maintained in a. rede: t'ermined setting by the'latching of t e bar over the edge 46a of slot 46. vThe levers 44 which project. from the coupling heads 43 connect to the bar 45 by means of links 450, and 4511, by which the entire group of coupling heads may be moved simultaneously to a selected position. v

I provide locking means 80 on the frame 11 in the form of detents which slide into notches formed in the frame 4 to maintain an inductance unit in a particular position when frame 11 has been moved'to such position.

It will be observed that connections ma be established for the conduction of uid through a selected inductance unit at the same time that the inductance unit is electrically connected in circuit with the associated parts of the radio transmitter. The shifting of the transmitter from one frequency to another frequency may be rapidly accomplished and high efliciency in the transmitter maintained.

While I have described my invention in certain preferred embodiments I desire that it be understood that modifications may he made and that no limitations upon my invention are intended other than are imposed by the scope of the appended claims.

- What I claim as new and desire to secure biy {Jetters Patent of the United States is as f ows:

1. In a variable inductance system, a rotat-' able frame, a plurality of inductance units of difierent inductance values carried by said rotatable frame, each of said inductance units being constituted by fluid conducting tubes, fluid connections for the ends of said tubes terminating adjacent said frame, and means for shifting'said frame into position for establishing connection between the ends of said inductance units and the fluid supply terminals adjacent said frame.

2. An inductance system comprising a rotatable frame, a plurality of inductance units carried by said frame, each of said inductance units comprising a tubular conductive-memher having terminal connections at opposite ends thereof, fluid circulation terminals fixed adjacent said frame, and means for connecting the ends of a selected one of said inductanceunits with said fluid circulation terminals for the passage of a cooling fluid through a selected inductanceunit.

3. An inductance system comprising a frame structure of insulating material, inductance units of different values carried by said frame structure, each of said inductance units comprising a fluid circulating conductive tubing having inlet and outlet terminals con-N nected thereto, fluidcirculation pipes fixed adjacent said frame, and means for establishing' connection between the inlet and outlet terminals of a selected one of said inductance units with said fluid circulation pipes for the passage of cooling fluid through selected ones of said inductance units.. v

. 4. In an inductance system, a rotatable frame of insulating material, means for mounting said frame for roekable movement with respect to an adjacent support, a multiplicity of inductance units carried by said frame structure, each of said inductance, units being constituted by a hollow conductive tubing having inlet and outlet connections at opposite ends thereof, fluid supply terminals carried by said adjacent support, and means for establishing connection between said fluid supply terminals and the ends of a selected one of said inductance unitsfor the passage of a cooling fluid through a selected inductance unit. I

5. An inductancesystem comprising a roinductance units carried on the periphery of said frame structure, each of said inductance units being constituted by a fluid circulating tubing having terminals for the supply and discharge of cooling fluid, a set of fixed fluid supply and discharge terminals positioned adjacent said frame structure, said frame structure being roekable to move the terminals of a selected inductance unit into align-' ment with said fixed fluid supply and discharge terminals for the circulation of a cooling fluid through a selected inductance unit.'

6. An inductance system comprising a r0- tatable frame structure of insulating material, inductance units of different values carried by the periphery of said rotatable frame structure, each of said inductance units being constituted by a conductive tubing having inlet and discharge fluid passages connected thereto, fluid delivery and discharge terminals positioned adjacent said rotatable frame structure, said rotatable frame struc-. I ture being angularly movable for aligning the fluid passages of a selected inductance unit with said fluid delivery and discharge terminals, and means for coupling said terminals and fluid passages for the circulation of fluid through a selected inductance unit.

7. An inductance system comprising a frame structure of insulating material mounted for rotative movement on a central shaft, a multiplicity of inductances-of differing values supported upon the-periphery of said rotatable frame structure, each of said,

inductances being constituted by conductive tubes having inlet and delivery passages, a set of fixed fluid inlet and discharge terminals mounted adjacent said frame structure, said discharge terminals, and coupling means operative to maintain said fluid passages 1n fluid tight relation to said inductance units.

8. An inductance system comprising a frame, a rotatable shaft journaled in said frame, a rotaryframe carried by said rotatable shaft, a multiplicity of inductances of different electrical values supported on the periphery of said frame, saidinductances each comprisng'a conductive tubing having fluid inlet and discharge passagestherein, a set of fixed fluid delivery and outlet terminals positioned adjacent said frame and aligned with the inlet and discharge passages-on said inductances, means for shifting said frame for moving the'inlet and discharge passages on said inductances into or out of engagement with said fixed fluid and outlet terminals, and coupling means operable to maintain said fixed terminals in connection with the passages on a selected inductance for the circulation of cooling fluid therethrough. tatable frame structure of insulatingmaterial,

9. An inductance system comprising a frame, a rotatable shaft journaled in said I frame, a rotary frame carried by said rotataand means for looking a selected inductance with respect to said fluid delivery and discharge terminals for the passage ofa cooling fluid therethrough.

10. In an inductance system, a frame structure, a multiplicity of-inductances carried by said frame structure, each of said inductances being constituted by a conductive tubing having inlet and discharge fluid passages therein,a set of fixed fluid delivery and discharge terminals mounted adjacent said frame structure, said frame structure being movable to align the passages on a selected inductance with said terminals, and valves carried in said terminals and in the passages in said inductances for normally closing said terminals'and passages, said valves operating to open a fluid paththrough said terminals and inductances when said passages are couculatory path for cooling fluid througli a selected inductance unit.

LOUIS A. GEBHARD.

central shaft being angularly movable with-r in predetermined limits for aligning the fluid inlet and delivery passages on a selected inductance unit-with the fixed fluid inlet and 

